Several types of samplers are known which allow consumers to test a product before purchasing a full size container. Often, businesses such as those in the cosmetic industry obtain new customers by distributing samples of their products to potential customers. Samplers are commonly available in retail stores or are distributed in magazines or through the mail.
Samplers are well known in the art. U.S. Pat. No. 5,072,831 to Parrotta et al., for example, provides a layer of sample material on a flat, paper-stock sheet that is coated with a barrier layer. A removable, transparent cover protects the sample material and allows consumers to see the sample before opening the sampler. To apply the sample material, a user must first rub it off the sampler with her finger.
The application of non-waxy powder materials to the sampler substrate presents special problems. Powder materials, such as may be found in cosmetics, are composed of dry particulate matter and must present a dry, non-oily appearance when applied to the user's skin.
U.S. Pat. Nos. 4,752,496 and 4,925,667 to Fellows et al., disclose cosmetic samplers for use in direct mailers or magazines where a cosmetic slurry containing a cosmetic, a carrier and a film forming agent is printed onto a substrate. The liquid carrier then evaporates leaving the cosmetic adhered to the substrate. U.S. Pat. No. 5,562,112 to Gunderman et al., discloses a similar invention wherein a slurry containing a cosmetic, a carrier and a binder is printed onto a substrate and covered with a thin film overlay.
One problem encountered in preparing samplers for powder cosmetics and other dry particulate materials is adhering the powder or other particulates to each other and to the substrate. This problem has been overcome in the art by the use of "binders" which cause the particulates to stick to each other and to the substrate. In many cases, however, binders are not used in the product itself, and thus the use of binders in the samplers changes the attributes of the sample material. In some cases the essential characteristics of the sample are no longer the same as the product. Such a sample is useless to a potential consumer.
Conventional application methods include such processes as screen printing, flexographic and engraved roll printing. These processes apply the sample material by positive pressure of a printing roll or screen pressing the sample admixture onto the substrate. When the substrate is removed from the roll or screen, the sample is pulled in opposite directions by the roll and the substrate. This effect disturbs the density packing of the sample material by weakening the cohesive bonds between the sample material and the substrate limiting the thickness of the sample material layer that may be applied. As a result, the amount of sample material that may be applied using conventional methods is too little to allow the consumer to adequately evaluate the suitability of the sample material.
Printing of attractive designs with a dry cosmetic is particularly problematic. Current printing methods require that rollers or screens used in the printing process be inscribed or cut with the pattern to be printed on the substrate. In the event of a change of pattern or a decision to make the layer of sample material thicker, expensive reconfiguring of the printing presses must be undertaken. Further expense and inconvenience results from the time taken to change and reconfigure the printing process to meet the new printing requirements.
Current methods of application do not permit multiple layers of sample material to be applied to the substrate. As previously described, the density packing of sample material is disturbed when the screen or roller separates from the material deposit. Application of multiple layers presents the same problem. Printing another layer of sample material using conventional methods would require additional binders or films or would result in the deposit falling off the substrate.